diff --git a/src/axolotl/core/trainers/grpo/__init__.py b/src/axolotl/core/trainers/grpo/__init__.py
index 1b240c6b4..d8e6140ed 100644
--- a/src/axolotl/core/trainers/grpo/__init__.py
+++ b/src/axolotl/core/trainers/grpo/__init__.py
@@ -131,7 +131,7 @@ class GRPOStrategy:
         return None
 
     @classmethod
-    def get_blocklist_args_kwargs(cls):
+    def get_blocklist_args_kwargs(cls) -> list[str]:
         return ["dataset_num_proc", "max_length"]
 
     @classmethod